Clinical journal of the American Society of Nephrology : CJASN
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Clin J Am Soc Nephrol · Feb 2018
Multicenter Study Comparative StudyUrine Anion Gap to Predict Urine Ammonium and Related Outcomes in Kidney Disease.
Low urine ammonium excretion is associated with ESRD in CKD. Few laboratories measure urine ammonium, limiting clinical application. We determined correlations between urine ammonium, the standard urine anion gap, and a modified urine anion gap that includes sulfate and phosphate and compared risks of ESRD or death between these ammonium estimates and directly measured ammonium. ⋯ Urine anion gap is a poor surrogate of urine ammonium in CKD unless phosphate and sulfate are included in the calculation. Because the modified urine anion gap merely estimates urine ammonium and requires five measurements, direct measurements of urine ammonium are preferable in CKD.